A huge rock carving in memory of Kim Il-sung, the father of North Korea, has been unveiled, as the impoverished country prepared a lavish celebration of this month's 100th anniversary of his birth.

The inscription covering a length of 122 feet was hewn into a natural rock face near Pakyon Falls in Kaesong city, near the border with South Korea, the official news agency said.

The message – "Our eternal leader Comrade Kim Il-sung: Dedicated to the centenary of the birth of the leader, April 15, Juche 101 (2012)" - is "an immortal monument which will always shine along with the Songun era", the news agency said.

Songun is North Korea's military-first policy.

Kim Il-sung died in 1994 and handed power to his son Kim Jong-il, who died last December after bequeathing the leadership to his own son Kim Jong-un.

North Korea, which fosters a massive personality cult surrounding the Kims, has inscribed messages praising the dynasty on hundreds of rocks and cliffsides.